Technical Field
The present invention relates to a semiconductor device, a method for manufacturing the same and a power converter
Description of the Related Art
As is generally known, in the process of manufacturing a semiconductor device (semiconductor element) using a group III nitride such as gallium nitride (GaN), it is difficult to form a group III nitride-based p-type semiconductor by ion implantation.
JP 2008-205315A and JP 2008-135700A disclose a technique of implanting a p-type impurity into a group III nitride-based semiconductor layer by ion implantation and subsequently heating the semiconductor layer in an atmospheric gas including nitrogen (N2).
JP 2009-170604A discloses a technique of implanting a p-type impurity into a group III nitride-based semiconductor layer by ion implantation and subsequently heating the semiconductor layer in an atmospheric gas including ammonia (NH3).
JP 2014-41917A discloses a technique of implanting a p-type impurity into a group III nitride-based semiconductor layer by ion implantation and subsequently heating the semiconductor layer in an atmospheric gas having varying flow rates of a reducing gas (for example, hydrogen (H2) and a nitrogen source gas (for example, ammonia (NH3)).
The techniques disclosed in JP 2008-205315A, JP 2008-135700A, JP 2009-170604A and JP 2014-41917A, however, have a problem that the area of the group III nitride-based semiconductor layer in which the p-type impurity is implanted is not effectively activated as the p-type semiconductor. There is accordingly a need for a technique that enables a group III nitride-based p-type semiconductor to be effectively formed by ion implantation. Other needs with regard to the semiconductor device include cost reduction, miniaturization, easy manufacture, resource saving, improvement of usability and improvement of durability.